None of this really has a thing to do with religion, it has to do with a grab for power. Religion is only the tool they use to obtain that power. They use God as a weapon and a handy excuse.
There are a number of reasons for this ~ some of them are cultural, and some historic, but primarily the biggest reason is the "leadership principle" ~ Shia has a tradition of disaggregated leadership, with authority deriving from a group ~ the religious leadership in fact.
Sunni is a sitting duck for any restatement of the forms the Roman Empire adopted. That includes the exact same "leadership principle" found in fascism and its twin, Nazism, or it's first cousin, Stalinism!
So, what was it you were sayng until you brought up a new topic?